At mine and quarry sites, information on the topographical features of the sites is important for excavation scheduling and production control. Therefore, a vehicle provided with GPS was conventionally travelled at the site of excavation to obtain three-dimensional position data, and the obtained three-dimensional position data was used to measure topographical features.
Although such a method can measure the features of the ground surface where the vehicle can travel but cannot measure the features of the ground or working face to be excavated or worked.
The present invention was achieved in view of the circumstances described above. It is an object of the invention to provide a topography measuring device which can efficiently measure the topographical features of a mine, ground, working face or the like where the vehicle cannot travel.